Sexless relationships are becoming increasingly prominent among young couples, with 28 percent of men in their 30s having sex less than once a month, a lifestyle survey has found.

The Internet based survey, conducted by medical-based advertising agency Dentsu, Sudler & Hennessey Inc., found that many respondents claimed stress from work, and a lack of fulfillment in their daily lives led to their sexlessness. The poll also highlighted a lack of energy among young people.

A total of 16 percent of men in their 20s were sexless, compared with 38 percent of men in their 40s, the survey found. "Sexless" is defined as having no sex or sex less than once a month.  More on MSN